I never understand this viewpoint — I understand what you're saying but there's no advantage to this over the Play Store model on Android.
You can have the walled garden, and also not restrict people's freedom — on Android I'm sure the number of people that use any other store than the play store or even side load apps are vanishingly small.
To even be able to do it you have to enable it deep in the settings. And even then, if a new app tries to install an apk you have to manually approve that app's ability to do that before reinitiating the entire process.
That's to say, the default experience is very wall gardened, and I do feel somewhat more protected when downloading something from the play store than not, and the vast majority of people will never leave the Google walled garden. But there exists a way to go around that walled garden when you need to, and that doesn't subtract from that walled garden mode in any way IMO.
